$A=\{1,2,3\}$
$R=\{(1,2)\}$
Since $(1,1)(2,2)(3,3) \notin R$
R is not reflexive
$(1,2) \in R$ but $(2,1) \notin R$
R is not symmetric
$(1,2) \in R$ but $(2,1) \notin R $ and $(1,1) \notin R$
Therefore r is not transitive
Solution:Therefore 'D'option is correct